This project will examine the distribution, severity, and health and nonhealth determinants of chronic disease and disability among children to provide a basis for assessing and planning programs to prevent handicapping conditions in childhood. The project first will study the major childhood chronic diseases, particularly those that result in limitation of activity. Data from the Health Interview Survey (HIS) will be used to specify current levels and determine whether the following have changed over time: 1) the proportion of children with chronic conditions, 2) the proportion of children with chrnoic conditions who report limitation of activity and 3) the severity of limitation among children with some degree of limitation. This initial research will investigate whether the reported near-doubling of disabled children in the past decade is due to increased prevalence of chronic conditions, survey or data artifacts, or increased public awareness resulting from new programs. Second, health and nonhealth factors associated with the development and the severity of chronic disorders will be studied using both HIS and the second Health and Nutrition Examination survey (HANES II). Multivariate techniques will permit analysis of which factors (personal, family, environmental, behavioral, health care and nutritional) are associated with the likelihood of a child having a chronic condition, and whether ineractions among factors affect the probability of chronic disorders. These results will then be used to refine a prevention framework for analyzing the determinants of chronic conditions. This framework will differentiate health and nonhealth factors associated with general and specific chronic conditions; the behavioral and nonbehavioral causes related to chronic conditions; and the predisposing, enabling and reinforcing factors affecting the development and severity of chronic conditions. Analysis of factors amenable to primary and secondary prevention will provide criteria that will be used to assess the scope and direction of existing prevention efforts and to identify additional targeted efforts that could be useful in reducing the level of chronic disease and disability in children. The long term significance of the proposed study is that the new epidemiologic information on chronic conditions in childhood will provide a better diagnostic approach to analyzing childhood disabilities and designing better prevention programs.